JPH04246639A - Camera using film provided with magnetic storage part - Google Patents

Abstract

PURPOSE:To increase recording capacity in the case of recording information for one frame and to drastically lower the reproducing error rate of the information. CONSTITUTION:A multiple recording control means which controls the write polarity of a magnetic head 6 every unit of one kind of information which should be written and multiply records the information in which the information unit is taken as one bit in the magnetic storage part of the film is provided in a control means (circuit) 103 for controlling the magnetic head 6 in a self- clock system.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera using a film with a magnetic storage section, which is equipped with a magnetic head for writing information into the magnetic storage section of the film.

0002

[Prior Art] In recent years, a camera that uses a film equipped with a magnetic storage section and writes and reads information using a magnetic head in a self-clocking manner has been disclosed in US Pat. No. 4,876,697.
Disclosed by No.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, the film feeding method of the camera was not originally designed with magnetic recording in mind, so the feeding speed was not stable and recording was not possible. It is unavoidable that the readout error of recorded information is higher than that of a normal recording/reproducing device such as a tape recorder. Therefore, when an attempt is made to read, for example, photographed information stored in the magnetic storage section of the film using a magnetic head, the higher the density of the information recorded, the higher the error rate becomes. There was a risk that appropriate photography would not be possible.

Furthermore, since the length of one frame (one frame) is limited, the amount of information that can be written in this frame is also limited.

[0005] In view of the above points, an object of the present invention is to increase the recording capacity of information and to significantly reduce the reproduction error rate of the information.

[0006]

[Means for Solving the Problems] The present invention provides a method for controlling the write polarity of the magnetic head for each type of information unit to be written in a control means for controlling the magnetic head in a self-clocking manner. A multiple recording control means is provided for multiple recording information in units of one bit onto the magnetic storage section of the film.

[0007]

[Operation] The multiplex recording control means can record, for example, subject brightness information,
The write polarity of the magnetic head is controlled for each type of information unit to be written, such as shutter speed information, and information in which each information unit is 1 bit is multiplexed onto the magnetic storage section of the film. In other words, each information such as object brightness information and shutter speed information is controlled as usual, but at this time, object brightness information is written using the positive electrode, shutter speed information is written using the negative electrode, and so on. Write polarity (positive, negative) for each information unit, which is easy to control and reproduce.
This allows new information to be written.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a view showing a camera according to a first embodiment of the present invention using a film having a magnetic storage section, with the back cover removed.

In FIG. 2, 1 is a camera body, 2 is a finder, 3 is a film cartridge chamber, 4 is a fork for rewinding the film into the film cartridge, 5 is a film aperture, and 6 is a fork for rewinding the film into the film cartridge. A magnetic head writes or reads information using a self-clocking method, 7 a film take-up spool, and 8 a photointerrupter for detecting perforations in the film.

FIG. 1 is a circuit block diagram showing a schematic configuration of the camera shown in FIG. 2. As shown in FIG.

In FIG. 1, 101 is a photometering circuit that measures the brightness of the subject to be photographed, 102 is a distance measuring circuit that measures the distance to the subject necessary for adjusting the focus of the photographic lens, and 103 is a camera. 104 is a switch (hereinafter referred to as SW1) that is turned on when the release button of the camera (not shown) is turned on when the release button is pressed; 105 is a control circuit that controls various circuits of the camera; 106 is a switch that is turned on and off in conjunction with the opening of the back cover (hereinafter referred to as SW2), 107 is a switch that detects the presence or absence of a film cartridge (not shown).

108 is an encoder that detects the film position from the output state of the photointerrupter 8; 109 is a motor control circuit that controls a film feeding motor (not shown); The film is rewound by reversing. 110 is a shutter control circuit for controlling exposure to the film; 111 is a lens control circuit for controlling the lens barrel so that the subject is in focus; 112 is for controlling the magnetic storage section of the film using the magnetic head 6 shown in FIG. A head control circuit 108 for writing information and reading information therefrom is an encoder that generates a pulse train according to the output state of the photointerrupter, that is, the amount of film feeding. Reference numeral 113 denotes a halfway rewind switch that is used when rewinding the film after shooting halfway through the film. When the halfway rewind switch 113 is turned on, the film feed mode is activated via the motor control circuit 109. The fork 4 is rotated by the motor, the film is wound into the film cartridge, and the film cartridge becomes ready to be taken out from the camera.

FIG. 3 is a diagram for explaining the film used in the present invention. In FIG. 3(a), 32 is a film, 31 is a perforation, 33 is a photographic frame, and 34 is a magnetic field. This is the recording department.

FIG. 3(b) shows a state in which a plurality of pieces of magnetic information (the same information or different information) are recorded in the magnetic storage section 34, with the polarity reversed for each block. It also shows that new information is recorded by reversing the polarity for each block.

FIG. 3(c) shows one information block in more detail, and consists of a signal SYNC for detecting synchronization, then an ID indicating the content of the information, and then information DATA. There is.

Since the present invention uses clock detection to determine polarity, the signal SYNC consisting of "0" and "1" is effectively used.

FIG. 4 is a diagram for explaining the reproduction of information recorded by the magnetic head 6. As shown in FIG.

FIG. 4(a) shows an analog waveform of a signal detected by the magnetic head 6, and FIG. 4(b) shows the state of magnetic recording based on this analog waveform. Figure 4(b)
), the one whose polarity changes from "S" to "N" is the clock (see Figure 4(c)), and the one whose polarity changes from "N" to "S" is the data (see Figure 4(d)). ). As is clear from FIG. 4(c), the clocks are approximately at equal intervals, and as is clear from FIG. 4(d), the data intervals vary.

FIGS. 4(e), (f), and (g) are similar to FIG. 4(a).
) is reversed and the peak is recorded upside down. In other words, the magnetic recording state is the state shown in FIG. 4(e), which is the opposite of FIG. 4(b), and in this case, "N" → "S" is the clock (see FIG. 4(f)).
, and "S" → "N" is data (see Figure 4 (g))
It is. As before, the clocks are approximately equally spaced;
The data intervals are irregular.

FIG. 5 is a flowchart showing the operation of control circuit 103 shown in FIG. "Step 1" The state of the switch SW1 linked to the release button of the camera is determined, and if it is ON, the process goes to step 2, and if it is OFF, the process stays at this step. "Step 2" The photometry circuit 101 is operated to obtain photometry data, and the distance measurement circuit 102 is operated to obtain distance measurement data. "Step 3" The state of the switch SW2 interlocked with the release button is determined, and if it is ON, proceed to step 4, and if it is OFF, return to step 1. "Step 4" The lens control circuit 111 is operated based on the distance measurement data obtained in step 2 to perform focusing. "Step 5" The shutter control circuit 110 is operated based on the photometric data obtained in step 2, and the film is exposed. "Step 6" The film feed motor is driven via the motor control circuit 109 to start winding the film and proceed to the next photographic frame. "Step 7" Configuration (block) shown in Figure 3(c)
The information to be recorded is input into a shift register or the like. The information contents here include subject brightness, shutter speed, etc. "Step 8" Input 1 bit of polarity information. The information contents here include frame numbers and photographed information.

Since each block contains one bit of this information, it is written over several blocks with the polarity being controlled (see "10001" in FIG. 3(b)). "Step 9" Determine whether or not the information input in steps 7 and 8 has been completed, and if it has been completed, proceed to step 12.
If the process has not finished, proceed to step 10. "Step 10" The write polarity of the next block is set, and the information input in step 7 is sequentially transmitted by the magnetic head 6 via the head control circuit 112 as shown in FIG. 4(b) or FIG. 4(e). Write. "Step 11" It is determined whether writing for one block has been completed, and upon completion, the process returns to step 7. "Step 12" It is determined whether or not one frame has been wound. When winding is completed, the process proceeds to step 13. "Step 13" The drive of the film feeding motor is stopped via the motor control circuit 109, that is, the winding of one frame of film is stopped. After that, return to step 1.

Note that rewinding at the end of the film is omitted.

FIG. 6 is a circuit block diagram showing the main parts of a second embodiment of the present invention.

In FIG. 6, 61 is a shift register into which polarity data is input, and 62 is information DA such as shutter speed.
63 is a shift register to which TA is input in parallel; 63 is a shift register to which ID indicating the type of information DATA is input in parallel; 64 is a shift register to which signal SYNC is input in parallel; 65 is a duty control circuit;
6 is an exclusive or gate, and 67 is an oscillator. 68 is a counter, and shift registers 62, 63,
When all 64 bits have been counted, the next data is input in parallel to the shift registers 62, 63, and 64, and the next polarity data is input to the shift register 61.

In the above configuration, the shift registers 64, 63, 62 are synchronized with the clock signal from the oscillator 67.
(SYNC, ID, DATA) in the order of one bit at a time, that is, a signal whose pulse rise is controlled according to “0” and “1” as shown in FIG. 4(b) is used as the duty control.
is output to the exclusive circuit 65, and from there the exclusive circuit 66
are sequentially output to one input terminal of the . In addition, the polarity data to be written is input to the other input terminal of the exclusive 66 (
One bit of data indicating information such as a frame number, etc. is inputted one by one (one bit at a time), and therefore, depending on the polarity, information for each block is recorded as shown in FIG. 4(b).

FIG. 7 shows a third embodiment of the present invention, and shows only the parts related to information reproduction of a camera equipped with a function of reproducing recorded information as shown in FIG. 4(b). Showing operation. The configuration of the camera may be the same as that shown in FIGS. 1 and 2, and can be realized by partially changing the flowchart of the control circuit 103.

The operation of the main parts will be explained below according to this flowchart. "Step 71" Information is reproduced by the magnetic head 6 via the head control circuit 112. "Step 72" Determine whether or not there is an edge in the playback signal input in step 71. If there is no edge, step 84
If there is, the process advances to step 73. "Step 73" It is determined whether the edge detected in step 72 is a rising edge or a falling edge, and if it is a rising edge, the process proceeds to step 74, and if it is a falling edge, the process proceeds to step 80. "Step 74" Store the time Δt2n from the previous rising edge to the current rising edge. “Step 75” The time Δt2n and the time Δt2(
n-1) are substantially the same, and if they are substantially the same, the process proceeds to step 83; otherwise, the process proceeds to step 76. Note that the time Δt2(n-1) is the time from the previous rising edge to the previous rising edge. "Step 76" Time Δt2n and time Δt2(n-
Since there is a difference in 1), it can be determined that it is a data edge as explained with reference to FIG. "Step 77" DATA edge indicating data changes from rising to falling (or from falling to rising)
Determine whether it has changed or not. If it has not changed, proceed to step 84; if it has changed, proceed to step 79.
Proceed to. "Step 79" After the DATA edge changes, it is determined whether the same direction of the DATA edge has continued for a predetermined pulse or more. If the DATA edge has continued for a predetermined pulse or more, the process proceeds to step 78. If the DATA edge has not continued for a predetermined pulse or more, the DATA edge direction is changed. The change is treated as a reading error and the process proceeds to step 84. "Step 78" Store the polarity of the DATA edge.

If it is determined in step 73 that the edge is not a rising edge, the process proceeds to step 80 as described above. "Step 80" Store the time Δt(2n+1) from the previous rising edge to the current rising edge. "Step 81" Determine whether the time Δt(2n+1) and the time Δt(2n-1) are substantially the same, and if they are substantially the same, proceed to step 83; otherwise, proceed to step 82.
Proceed to. “Step 82” Time Δt2n and time Δt(2n−
Since there is a difference in 1), it can be determined that it is a data edge as explained with reference to FIG.

If it is determined in steps 75 and 81 that the respective times are approximately equal, the process proceeds to step 83 as described above. “Step 83” Here, with the first read data “
Until a data change of 0 or 1 appears, it is unclear which side of the edge is the data, so it is determined whether the edge of the data has already been determined, and if it is uncertain, the process proceeds to step 71. Return and if the determination has been completed, proceed to step 84. "Step 84" Here, the SYNC within one block
, ID, and DATA bit by bit and stored. "Step 85" It is determined from the output from the encoder 108 whether or not one frame's worth of feeding has been completed. If not, the process returns to step 71. If it has been completed, the information stored in steps 76 (or 82) and 84 will be treated as information of the current frame.

[0030]

[Effects of the Invention] As explained above, according to the present invention,
Within the control means that controls the magnetic head in a self-clocking manner, the write polarity of the magnetic head is controlled for each type of information unit to be written, and the information in which the information unit is 1 bit is stored in the magnetic storage section of the film. A multiplex recording control means for multiplex recording is provided, and the write polarity of the magnetic head is controlled for each type of information unit to be written, such as object brightness information, shutter speed information, etc., and each information unit is set as one bit. Information is multiplexed onto the magnetic storage section of the film. Therefore, the information storage capacity can be increased,
Furthermore, it is possible to significantly reduce the reproduction error rate of that information (because it is only necessary to determine the polarity).

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing a schematic configuration of a camera in a first embodiment of the present invention.

FIG. 2 is a back view of the camera according to the first embodiment of the present invention with the back cover removed.

FIG. 3 is a diagram illustrating a film with a magnetic memory portion used in the present invention.

FIG. 4 is a diagram illustrating a case where information recorded on the film shown in FIG. 3 is reproduced.

FIG. 5 is a flowchart showing the operation of the control circuit of FIG. 1;

FIG. 6 is a circuit block diagram showing the configuration of main parts in a second embodiment of the present invention.

FIG. 7 is a flowchart showing operations of main parts in a third embodiment of the present invention.

[Explanation of sign]

6 Magnetic head 61, 62, 63, 64 Shift register 65
Duty control circuit 66 Exclusive or gate 68 Counter 103 Control circuit 108 Encoder 109 Motor control circuit 112 Head control circuit

Claims (1)

[Claims] Claim 1: A magnetic head that writes information to a magnetic storage section provided on a film;
In a camera using a film with a magnetic storage unit, the camera is equipped with a control means for controlling the magnetic head in a self-clocking manner, and the control means is configured to set the write polarity of the magnetic head for each type of information unit to be written. 1. A camera using a film with a magnetic storage section, characterized in that a multiplex recording control means is provided to control and multiplex record information in which one information unit is 1 bit in the magnetic storage section.